diff options
| -rw-r--r-- | xen/arch/x86/xstate.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c index a64a832998..1cc3e375d0 100644 --- a/xen/arch/x86/xstate.c +++ b/xen/arch/x86/xstate.c @@ -342,6 +342,7 @@ int validate_xstate(u64 xcr0, u64 xcr0_accum, u64 xstate_bv, u64 xfeat_mask) int handle_xsetbv(u32 index, u64 new_bv) { struct vcpu *curr = current; + u64 mask; if ( index != XCR_XFEATURE_ENABLED_MASK ) return -EOPNOTSUPP; @@ -355,9 +356,23 @@ int handle_xsetbv(u32 index, u64 new_bv) if ( !set_xcr0(new_bv) ) return -EFAULT; + mask = new_bv & ~curr->arch.xcr0_accum; curr->arch.xcr0 = new_bv; curr->arch.xcr0_accum |= new_bv; + mask &= curr->fpu_dirtied ? ~XSTATE_FP_SSE : XSTATE_NONLAZY; + if ( mask ) + { + unsigned long cr0 = read_cr0(); + + clts(); + if ( curr->fpu_dirtied ) + asm ( "stmxcsr %0" : "=m" (curr->arch.xsave_area->fpu_sse.mxcsr) ); + xrstor(curr, mask); + if ( cr0 & X86_CR0_TS ) + write_cr0(cr0); + } + return 0; } |